Content Encoding Error in parts of the manager after upgrading to Evolution?

<?php
/**
 * get_lang_options
 *
 * returns html option list of languages
 * 
 * @param string $key specify language key to return options of langauges that override it, default return all languages
 * @param string $selected_lang specify language to select in option list, default none
 * @return html option list
 */
function get_lang_options($key=null, $selected_lang=null) {
    global $lang_keys;
    if($key) {
        $languages = get_langs_by_key($key);
        sort($languages);
        ob_start();
            echo <<<OPTION
                <option value="">{$_lang['language_title']}</option>

OPTION;
        foreach($languages as $language_name) {
            $uclanguage_name = ucwords(str_replace("_", " ", $language_name));
            echo <<<OPTION
                <option value="{$language_name}">{$uclanguage_name}</option>

OPTION;
        }
        return ob_get_clean();
    } else {
        $languages = array_keys($lang_keys);
        sort($languages);
        foreach($languages as $language_name) {
            $uclanguage_name = ucwords(str_replace("_", " ", $language_name));
            $sel = $language_name == $selected_lang ? ' selected="selected"' : '';
            echo <<<OPTION
                <option value="{$language_name}" {$sel}>{$uclanguage_name}</option>

OPTION;
        }
        return ob_get_clean();
    }
}